MSc thesis: The role of bryophytes in regulating carbon, energy and water fluxes across climatic gradients

Alpine grasslands are vulnerable to climate change, and are currently changing rapidly in both plant functional group dominance (Engemann et al. 2016) and species distributions (Kelly and Goulden 2008). These biotic shifts contribute to indirect effect of climate change through influencing biotic interactions (Vandvik et al. 2020). Bryophytes are regulating soil temperature and moisture: they have an important role on soil micro-climate (Althuizen 2018) and consequently on soil processes such as litter decomposition (Petraglia et al. 2019), and soil function such as plant seedlings growth (Lett et al. 2017). New threats, such as climate change, will modify bryophyte species distribution through biotic and abiotic shifts. A recent study using a warming experiment showed that bryophytes may be the functional group the most impacted by climate warming ( van Zuijlen et al. 2021). Here, we would like to study how climate and plant composition influence bryophytes hydrological and thermal regulation properties to better anticipate future climate change impact. The collected data will also be used within large-scale climate models, where we are developing new approaches to representing the important role of moss and lichen in regulating fluxes of carbon, energy and water in the Norwegian Earth System model (NorESM) in order to improve representation of high-latitude ecosystems and their climate interactions.

The FUNDER and EMERALD projects
Climate change alters plant and soil communities, and interactions in the plant-soil food web. These changes pose threats to biodiversity and key ecosystem processes and functions, such as carbon and nutrient cycling, and ecosystem productivity. The FUNDER project assesses and disentangles the direct effects of climate from the indirect effects, mediated through biotic interactions, on the diversity and functioning of the plant−soil food web. We use a macro-ecological experimental approach to quantify the impacts of vegetation diversity on interactions and ecosystem functioning across factorial broad-scale temperature and precipitation gradients in western Norway. The objectives are to disentangle direct and indirect climate impacts on plants, soil nematodes and microarthropods, and microbes, and ecosystem processes. We aim to better understand landscape variation and whole-ecosystem consequences of indirect climate impacts as well as climate feedbacks of the plant-soil food web. EMERALD focuses on integrating data from field projects such as FUNDER into dynamic global vegetation models (CTSM-FATES), so as to better represent the role of vegetation-climate interactions in high-latitude ecosystems.

MSc project
This MSc thesis will be conducted as part of the FUNDER and EMERALD projects, where the MSc student will have responsibility for assessing key attributes of bryophyte communities across the FUNDER experimental sites. In addition to field-surveys of bryophyte communities and harvesting biomass across the climate grid (summer 2022), further lab-based opportunities include: investigating the impact of bryophytes on regulating hydrological processes through measuring the water holding capacity of bryophyte communities; assessing how the reflectance of bryophyte communities may shift according to their desiccation status or community composition; and how bryophytes moderate local thermal micro-climates. These characteristics can be used to in the EMERALD modelling to better predict how moss and lichen communities influence their surrounding microclimate environments, and how responses may vary depending upon the direct and indirect effects of climate.

Potential research questions
1. How does the biodiversity and functioning of bryophytes in alpine grasslands vary along broad-scale climate gradients?
2. Are the responses of this plant functional group to climate influenced or modified by biotic interactions?
You will be part of a dynamic research team, gather experience in scientific approach and have an amazing fieldwork experience in fjords and mountains in Western Norway.

• Fieldwork collecting above-ground biomass
• Lab work sorting bryophytes, weigh the biomass (fresh and dry), measuring water holding capacity, reflectance shifts and thermal properties of bryophytes
• Data management, reproducibility and Open Science practices
• Statistical analyses using R
• Scientific communication skills: write a thesis which can be published as a scientific paper and presented in national/international conferences

Candidate requirement
• Global change ecology background
• Interest for bryophytes ecology
• Scientific rigor on the field and in the lab
• Statistical and data management skills
• Scientific writing skill
• Team spirit
• Enjoy hiking in mountains and being outside under both sunny and rainy weather

Practical information
• Date: From July 2022 to December 2022
• Place of work: University of Bergen, Norway
• Supervisors: Sonya Geange, Morgane Demeaux and Vigdis Vandvik
• Application: CV and motivation letter at and before 2nd of May 2022

– Althuizen, I. 2018. ‘The Importance of Vegetation Functional Composition in Mediating Climate Change Impacts on Ecosystem Carbon Dynamics in Alpine Grasslands’. University of Bergen.
– Engemann, K., B. Sandel, B. J. Enquist, P. M. Jørgensen, N. Kraft, A. Marcuse-Kubitza, B. McGill, et al. 2016. ‘Patterns and Drivers of Plant Functional Group Dominance across the Western Hemisphere: A Macroecological Re-Assessment Based on a Massive Botanical Dataset’. Botanical Journal of the Linnean Society 180 (2): 141–60.
– Kelly, A. E., and M. L. Goulden. 2008. ‘Rapid Shifts in Plant Distribution with Recent Climate Change’. Proceedings of the National Academy of Sciences 105 (33): 11823–26.
– Lett, S., M.-C. Nilsson, D. A. Wardle, and E. Dorrepaal. 2017. ‘Bryophyte Traits Explain Climate-Warming Effects on Tree Seedling Establishment’. Journal of Ecology 105 (2): 496–506.
Petraglia, A., C. Cacciatori, S. Chelli, G. Fenu, G. Calderisi, Domenico Gargano, Thomas Abeli, Simone Orsenigo, and Michele Carbognani. 2019. ‘Litter Decomposition: Effects of Temperature Driven by Soil Moisture and Vegetation Type’. Plant and Soil 435 (1): 187–200.
– Vandvik, V., O. Skarpaas, K. Klanderud, R. J. Telford, A. H. Halbritter, and D. E. Goldberg. 2020. ‘Biotic Rescaling Reveals Importance of Species Interactions for Variation in Biodiversity Responses to Climate Change’. Proceedings of the National Academy of Sciences 117 (37): 22858–65.
– Zuijlen, K. van, K. Klanderud, O. S. Dahle, Å. Hasvik, M. S. Knutsen, Siri Lie Olsen, Snorre Sundsbø, and Johan Asplund. 2021. ‘Community-Level Functional Traits of Alpine Vascular Plants, Bryophytes, and Lichens after Long-Term Experimental Warming’. Arctic Science, April, 1–15.